_vcprintf_s, _vcprintf_s_l, _vcwprintf_s, _vcwprintf_s_l

Article
12/21/2012

Write formatted output to the console using a pointer to a list of arguments. These are versions of _vcprintf, _vcprintf_l, _vcwprintf, _vcwprintf_l with security enhancements as described in Security Features in the CRT.

Important

This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

int _vcprintf(
   const char* format,
   va_list argptr
);
int _vcprintf(
   const char* format,
   locale_t locale,
   va_list argptr
);
int _vcwprintf_s(
   const wchar_t* format,
   va_list argptr
);
int _vcwprintf_s_l(
   const wchar_t* format,
   locale_t locale,
   va_list argptr
);

Parameters

format
Format specification.
argptr
Pointer to list of arguments.
locale
The locale to use.

For more information, see Format Specifications.

Return Value

The number of characters written, or a negative value if an output error occurs.

Like the non-secure version of these functions, if format is a null pointer, the invalid parameter handler is invoked, as described in Parameter Validation. Additionally, unlike the non-secure version of these functions, if format does not specify a valid format, an invalid parameter exception is generated. If execution is allowed to continue, these functions return

Remarks

Each of these functions takes a pointer to an argument list, then formats and writes the given data to the console. _vcwprintf_s is the wide-character version of _vcprintf_s. It takes a wide-character string as an argument.

The versions of these functions with the _l suffix are identical except that they use the locale parameter passed in instead of the current locale.

Security Note
Ensure that format is not a user-defined string. For more information, see Avoiding Buffer Overruns.

Generic-Text Routine Mappings

TCHAR.H routine	_UNICODE & _MBCS not defined	_MBCS defined	_UNICODE defined
_vtcprintf_s	_vcprintf_s	_vcprintf_s	_vcwprintf_s
_vtcprintf_s_l	_vcprintf_s_l	_vcprintf_s_l	_vcwprintf_s_l

Requirements

Routine	Required header	Optional headers
_vcprintf_s, _vcprintf_s_l	<conio.h> and <stdarg.h>	<varargs.h>*
_vcwprintf_s, _vcwprintf_s_l	<conio.h> or <wchar.h>, and <stdarg.h>	<varargs.h>*

* Required for UNIX V compatibility.

For additional compatibility information, see Compatibility in the Introduction.

Example

// crt_vcprintf_s.cpp
#include <conio.h>
#include <stdarg.h>

// An error formatting function used to print to the console.
int eprintf_s(const char* format, ...)
{
  va_list args;
  va_start(args, format);
  return _vcprintf_s(format, args);
}

int main()
{
   eprintf_s("  (%d:%d): Error %s%d : %s\n", 10, 23, "C", 2111,
           "<some error text>");
   eprintf_s("  (Related to symbol '%s' defined on line %d).\n",
           "<symbol>", 5 );
}

(10,23): Error C2111 : <some error text>
  (Related to symbol '<symbol>' defined on line 5).

.NET Framework Equivalent

System::Console::Write

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